Wednesday, February 18, 2009

HeLa Cells

HeLa cells are known globally as one of the greatest medical discoveries of our time, and allowed for many - if not all - important medical advances that have occurred during this century. However, despite their unarguable medical importance, their existence is shrouded in controversy, whether it be in their origin, their continual usage, or in the revelation of their unique chromosome number. The story of HeLa cells begins with Henrietta Lacks, a young mother of five who lived in Baltimore during the 1940-50’s. On February 1st 1951, at Hopkins Hospital, Henrietta was found to have malignant cervical cancer. At the same time in the hospital, the Head of tissue culture research, George Gey, and his wife Margaret, where working to find a cure for cancer. They were sure that if they could culture a line of human cells that could live indefinitely outside of the body, then the cure would soon follow. A sample of Henrietta Lack’s cancer cells were taken, and a young resident who knew that the Geys’ where searching for a new sample to investigate, sent it to the George Gey. Henrietta’s cells turned out to be the break-through that Gey had been waiting for - her cells multiplied like no-one had ever seen before, reproducing an entire generation every 24hours; they were an immortal cell-line, with the acquired ability to proliferate continuously, without any mechanisms of prevention. Gey named the cells “HeLa cells”, in honour of their source’s name, but claimed them as his own discovery, and spent the rest of his life profiteering from them. This is when the first ethical dilemma arises; Henrietta Lacks had no idea that a sample of her tumour had been taken and sent to George Gey, and that her own cells would be used as a basis for medical research for decades to come. Her husband David knew that a sample had been taken, but was told that it was to see if the cancer was hereditary, and that it might help his children if the cancer struck again. Despite being told this, David Lacks never heard from the research team again. There is a question then, of whether appropriate consent was given. Having looked into this topic, however, I have found that there is no legal requirement to inform the patient or patient’s family in such a case, as any tissue obtained/removed by the physician during surgery, or indeed any medical procedure, in fact then becomes the property of the surgeon, to do with what he/she pleases. Personally, I find this to be an unorthodox rule, particularly in the case of Henrietta Lacks, when the physician in question profited so greatly from the sample he obtained. However, lack of informed consent was common in medical research at the time. On the 4th October 1951, Henrietta Lacks passed away, and on the same day George Gey appeared on national television with a vial of his “HeLa” cells, stating “It is possible that, from a fundamental study such as this, we will be able to learn a way by which cancer can be completely wiped out.” Soon after this statement was made in front of the American nation, the HeLa cell-line was used to propagate poliovirus, which then lead to the development of vaccines against polio, a medical triumph that saved thousands of lives, and one that could not have occurred where it not for the unique nature of HeLa cells. In this scenario, we can indeed classify HeLa cells as a “medical blessing” - the fact that Gey and his team managed to propagate the poliovirus so quickly lead to a surge of global interest in the HeLa cell line, and facilities to enable mass-production of HeLa cells was established by the National Foundation for Infantile paralysis. Soon samples of Henrietta’s cells were being bought and sold by millions world-wide, and even went up in the first space missions to see what would happen to human cells in zero gravity. Here the second ethical dilemma appears. Henrietta’s family had no idea that her cells were being used in such a way - they weren’t ever aware they were still alive. It wasn’t until 24 years after death, when her daughter in law heard about them from a scientist at a dinner party, that the issue came to their attention. The family were unable to afford a lawyer to take the case to court, and so nothing could be done about what the Lacks family believed to be a great injustice. One of Henrietta’s daughters is quoted to have said "We never knew they took her cells, and people done got filthy rich, but we don't get a dime" As I stated earlier, the HeLa cell-line can be classed as a “medical blessing” as they allowed for previously impossible medical research to be carried out. It can be argued, however, that HeLa cells turned out to be more of a medical curse. After the discovery of HeLa cells, as more and more laboratories began using human cells in culture, scientists were finding that since the introduction of HeLa cells, these other cell cultures also began to multiple indefinitely. For two decades research was done on what were thought to be normal human cells, for example placental cells, but in 1974 it was revealed that HeLa cells - due to their robust nature and ability to spread and multiply so considerably - had contaminated the world’s stock of cell cultures. This meant that billions had been spent on isolated tissue cultures, that turned out to be invalid as they were revealed to be HeLa cells. Although this caused obvious setbacks in the scientific world, I think that some good may have come out of it, as the methods of preparation and study of cell cultures has been vastly improved since then, meaning the potential for human error has been significantly reduced. Hopefully I have explained sufficiently the ethical and medical dilemmas surrounding the immortal HeLa cells, but what of the other question of the evolution of a post-human species? This question arises when we look at some of the unique features of HeLa cells; mainly that they are unarguably human - haven been extracted directly from a human source - but equally they have 82, instead of 46, Chromosomes in their nuclei (four copies of chromosome 12 and three copies of chromosomes 6, 8 and 17). In theory, if a HeLa cell could produce a gamete, it would not be able to fertilize with a human gamete (due to the different number of chromosomes) - which, by laws of classification, means that HeLa cells are an entirely new species - Helacyton gartleri - to use it’s proper given name. It would appear that through the mechanism of random mutations, the cervical cancer cells in Henrietta Lacks body found a selective advantage, that allowed them to proliferate indefinitely and to live for an extended length of time. But what is this selective advantage that has allowed HeLa cells to flourish? Research has shown that HeLa cells have an active form of the enzyme Telomerase (not present in normal cells, but can be found in most cancerous cells). Telomerase is active during cell division, and prevents the shortening of telomeres - a mechanism that is associated with ageing and eventual cell death. It may be argued then, that cancer cells are a mode of “microevolution“; the cells within us are subject to the same laws of natural selection as we are, with HeLa cells emerging as the next branch of the evolutionary tree. To conclude, I think that HeLa cells are all of an ethical nightmare, medical blessing, and evolution of a post-human species. The Lacks family never gave their consent for Henrietta’s cells to be used in research, neither did they receive any acknowledgment for the great medical advances Henrietta gave to the world. However, since the cells are technically not human, does the family have any right to them? Certainly this can be classified as an ethical nightmare.From looking at the medical advances HeLa cells have provided, I would agree that they are a medical blessing, especially in light of their ability to keep their telomeres intact, which is now being used in medical research to see if the same mechansim can elongate human life.

12 comments:

You've used "profiteering" in a perjorative sense, but have not given any sense of the profits that Gey might have made. Did you find any numbers?

I found the arguments balanced on the surface, but in the end could not determine what you concluded. In part that's the fault of the question, setting up three possibilities as if they are mutually exclusive. My sense is that you think HeLa cells pose an ethical nightmare -- but has waking from this nightmare had any effect on current practices?

You have misinformation in one section. At the beginning of the second paragraph you state that Henrietta Lacks had no idea her cells were taken... She wouldn't have. She died.And after the doctors pursuing her hiusband and saying that they could possibly help find a cure for cancer, her husband ok'd the physicians to obtain a post mortem sample of her cells. Otherwise the rest seems accurate.

So are we saying here that the hela cell line is the only one that can be cultured? Is it the only cell line ever to have been found with that capability?Are we really saying here that of all cancer patients since 1951 not a single one of them had a cancer cell line that could be cultured?

What about chromosomal studies of other cancer cell lines are there any abnormalities?Or is the problem the secrecy in the industry so large scale studies are hindered?